Palladium Catalyzed Intramolecular Vinylselenation and Vinylthiolation of Allenes
摘要:
Intramolecular vinylselenation of allenes 1a,b proceeds in the presence of Pd(0) catalyst producing pyridin-2-one derivatives 2a,b having a high degree of unsaturation as a sole product. This cyclization could also be applied to vinylthiolation and to the construction of seven-membered lactams.
Platinum-Catalyzed Intramolecular Vinylchalcogenation of Alkynes with β-Phenylchalcogeno Conjugated Amides
摘要:
Platinum-catalyzed intramolecular vinylthiolation and -selenation of internal alkynes with vinylchalcogenides 1 having a carbamoyl group on cis-beta-position of vinyl moiety was developed. The conjugated six-membered lactam framework 2 was constructed in 1 high yields. Density functional theory calculations for alkyne insertion processes suggest seven-membered platinacycle 3 is a kinetically favored intermediate of this catalytic system.